1. Field of the Invention
The present invention relates to a structure for absorbing a slack of a wire harness which is installed in order to supply electric power from a vehicle body to a sliding door or the like in an automobile, and more particularly to the structure for absorbing the harness slack accompanying opening and closing movements of the sliding door, by pressing the wire, harness by means of a plate-like resilient member, wherein fixation of the resilient member can be easily and reliably conducted.
2. Description of the Related Art
Heretofore, various apparatuses have been proposed in order to supply power, signals, etc. to a sliding door which is used in a one boxed car or on a rear seat side in a type of a passenger car, at any time irrespective of opening and closing movements of the sliding door.
Conventionally, a slack of an electric wire accompanying opening and closing movements of the sliding door has been absorbed, for example, by curling the electric wire, or by installing a plurality of electric wires (wire harness) along a pair of link arms so that the pair of the link arms can be bent and stretched with the opening and closing movements of the sliding door.
In case of the one boxed car, the wire harness including a power supply line is installed from the vehicle body side by way of a back of a step or its vicinity, extending from a lower part of the sliding door to an inside of the sliding door, and connected to various functional components in the sliding door, such as a power window motor, speaker, door lock unit, switch unit, etc.
When the sliding door is opened by sliding it backward, the sliding door is slid backward while moving outwardly away from the vehicle body, and a gap is created between the sliding door and the vehicle body. As the door side wire harness moves backward integrally with the sliding door, a large slack will occur in the wire harness with respect to the vehicle body. In order to absorb this slack, there is a need for the aforesaid slack absorbing apparatus. In case where the slack is not absorbed, there may be arisen such a danger that the wire harness may be caught between the sliding door and the vehicle body and damaged when the sliding door is closed.
As the sliding door is closed by sliding it forward, the door side wire harness is moved forward integrally with the sliding door and brought into a tensioned state.
However, in the conventional apparatus as described above, employment of the link arms, for example, would lead to problems such as a complicated structure and a bulky size. It has been concerned that this may incur high component cost and increased number in steps for assembling the apparatus to the sliding door, and that flexibility in arranging the functional components in the sliding door may be limited.
There has been also such an anxiety that, when the sliding door is closed violently, for example, the wire harness is pulled strongly and tends to be disengaged from the slack absorbing apparatus such as the link arms and so on. If the wire harness is disengaged, the slack of the wire harness will not be absorbed, and such an inconvenience that the wire harness may be caught between the sliding door and the vehicle body will occur.
In view of the above described circumstances, the object of the present invention is to provide a harness slack absorbing structure which is simple in structure and can be assembled easily and reliably, and free from such a fear that the wire harness may be disengaged from the slack absorbing structure, even though the sliding door is violently closed.
In order to achieve the above described object, there is provided, according to a first aspect of the present invention, a harness slack absorbing structure comprising a resilient member in a plate-like shape whose base end is fixed to a mounting part by means of a fixing member, and a wire harness installed along the resilient member, the resilient member being provided with a cut-out, the fixing member being provided with a slit to be engaged with the resilient member, wherein one end of the cut-out is abutted against a lower end of the slit, while the other end of the cut-out is abutted against a base end of the fixing member.
According to a second aspect of the present invention, the cut-out is provided on either side or both sides in a lateral direction of the resilient member.
According to a third aspect of the present invention, the mounting part includes an insertion part for receiving the resilient member, the insertion part being provided with a cut-out to be engaged with the fixing member.
According to a fourth aspect of the present invention, the fixing member is fixed to the mounting part by screw means.
According to a fifth aspect of the present invention, the fixing member is fixed to the mounting part through thermal deformation of projections which are formed of synthetic resin and provided on either of the mounting part and the fixing member.
According to a sixth aspect of the present invention, the mounting part includes a protector for receiving the wire harness in a curved state, the protector being provided in a sliding door or a vehicle body.
According to the first aspect, because the fixing member is fixed to the mounting part in a state where the plate-like resilient member has entered in the slit in the fixing member, the resilient member is held by inner edges of the slit in a direction of its thickness, and can be firmly supported without a backlash against bending force in a direction of the thickness of the resilient member. As the results, there will be no risk of rattle of the resilient member, disengagement of the resilient member from the mounting part, and wear of the mounting part due to repeated bending. Moreover, a length of the cut-out in the resilient member can be shorter by the length of the slit. This will enhance rigidity, bending strength, and tensile strength of the resilient member, and tear or plastic deformation of the resilient member due to the repeated contraction and expansion will be reliably prevented.
Further, abutting the one end of the cut-out against the lower end of the slit will block a movement of the resilient member toward its base end, and abutting the other end of the cut-out against the base end of the fixing member will block a movement of the resilient member toward its distal end in a longitudinal direction. Because the resilient member is fixed in this manner so as not to move in a longitudinal direction, withdrawal of the resilient member when bent or pulled can be reliably prevented. Accordingly, reliable absorption of a slack of the wire harness can be always attained, and an inconvenience such as a bite of the wire harness can be eliminated.
Further, because the harness slack absorbing apparatus is composed of a few components such as the plate-like resilient member and the fixing member, this will contribute to a simple structure, light weight, low cost, and facilitated assembling work.
According to the second aspect, in case where the cut-outs are provided on both sides of the resilient member, the plate-like resilient member can be engaged with the slit in the fixing member, irrespective of a front face and a back face of the resilient member, thus enhancing assembling workability.
According to the third aspect, by inserting the resilient member into the insertion part, the resilient member will be supported in a direction of the thickness resisting the bending force, and firmly held in cooperation with the supporting force of the aforesaid slit. Moreover, by engaging the fixing member with the cut-out in the insertion part in a state where the resilient member is engaged with the slit, the distal end of the fixing member is abutted against the one end of the cut-out in the insertion part, and the base end of the fixing member is abutted against the other end of the cut-out, enabling the resilient member to be firmly held in the insertion part resisting a tensile force in a longitudinal direction.
According to the fourth aspect, the fixing member is firmly fixed to the mounting part by the screw means in a state where the resilient member is held by the fixing member and the fixing member is held by the insertion part. As the results, even though a strong tensile force or bending force is exerted on the resilient member, the resilient member will be reliably prevented from being disengaged from the mounting part, and reliable absorption of a slack of the wire harness can be always attained.
According to the fifth aspect, by thermally deforming the projections made of synthetic resin, the fixing member can be simply and effectively fixed to the mounting part. At the same time, the component cost will be decreased and the fixing structure will be simplified, because the components such as small screws need not be employed.
According to the sixth aspect, the insertion part, the fixing member and the resilient member can be safely protected inside the protector from interference with the exterior. Moreover, a slack of the wire harness occurring with opening and closing movements of the sliding door can be absorbed by the resilient member inside the protector, and a catch of the wire harness between the sliding door and the vehicle body and accompanying damage of the wire harness will be prevented.